Материал из C\C++ эксперт
const double value
#include <iostream>
using namespace std;
int main()
{
double bottles;
cout << "How many bottles do you have? ";
cin >> bottles;
double cans;
cout << "How many cans do you have? ";
cin >> cans;
const double BOTTLE_VOLUME = 2.0;
const double CAN_VOLUME = 0.355;
double total = bottles * BOTTLE_VOLUME
+ cans * CAN_VOLUME;
cout << "The total volume is " << total << " liter.\n";
return 0;
}Define constant
#include <iostream>
using namespace std;
const int intCount = 100;
int main()
{
int empNums[intCount];
double salary[intCount];
char *names[intCount];
}Demonstrates constants
#include <iostream>
using namespace std;
int main()
{
const int ALIEN_POINTS = 150;
int aliensKilled = 10;
int score = aliensKilled * ALIEN_POINTS;
cout << "score: " << score << endl;
enum difficulty {NOVICE, EASY, NORMAL, HARD, UNBEATABLE};
difficulty myDifficulty = EASY;
enum ship {FIGHTER = 25, BOMBER, CRUISER = 50, DESTROYER = 100};
ship myShip = BOMBER;
cout << (CRUISER - myShip) << " Resource Points.\n";
return 0;
}Demonstrating the const type qualifier
#include <iostream>
using std::cout;
using std::endl;
void f( const int [] );
int main()
{
int a[] = { 10, 20, 30 };
f( a );
cout << a[ 0 ] << " " << a[ 1 ] << " " << a[ 2 ] << "\n";
return 0;
}
void f( const int b[] )
{
cout << b[ 0 ];
}1010 20 30
Same Program Using Constant Integers
#include <iostream>
int main()
{
const int Sunday = 0;
const int Monday = 1;
const int Tuesday = 2;
const int Wednesday = 3;
const int Thursday = 4;
const int Friday = 5;
const int Saturday = 6;
int today;
today = Monday;
if (today == Sunday || today == Saturday)
std::cout << "\nGotta" love the weekends!\n";
else
std::cout << "\nBack to work.\n";
return 0;
}Using a properly initialized constant variable.
#include <iostream>
using std::cout;
using std::endl;
int main()
{
const int x = 7;
cout << x << endl;
return 0;
}7
